Reviewing the previous study results, glutamine supplementation in parental form and with higher dose in various patient populations has shown evidence of being beneficial. Studies of enteral glutamine therapy have also showed benefits, but results are less consistent possibly because of the heterogeneous study methodology described above. Moreover, most of the studies are carried out in burn patients and surgical patients; there were few studies in critical ill medical patients. Finally no study has specifically looked at the mechanism via which glutamine has conferred protection.